720032121 has 6 divisors (see below), whose sum is σ = 1040046410. Its totient is φ = 480021408.

The previous prime is 720032111. The next prime is 720032123. The reversal of 720032121 is 121230027.

It can be written as a sum of positive squares in only one way, i.e., 700131600 + 19900521 = 26460^2 + 4461^2 .

It is not a de Polignac number, because 720032121 - 2⁷ = 720031993 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 720032094 and 720032103.

It is not an unprimeable number, because it can be changed into a prime (720032123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 40001776 + ... + 40001793.

Almost surely, 2^720032121 is an apocalyptic number.

It is an amenable number.

720032121 is a deficient number, since it is larger than the sum of its proper divisors (320014289).

720032121 is a wasteful number, since it uses less digits than its factorization.

720032121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80003575 (or 80003572 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 720032121 is about 26833.4142628179. The cubic root of 720032121 is about 896.2942775578.

Adding to 720032121 its reverse (121230027), we get a palindrome (841262148).

The spelling of 720032121 in words is "seven hundred twenty million, thirty-two thousand, one hundred twenty-one".